Duplikate gelöscht:

Das Include #include "Cluster/IDisplayClusterClusterManager.h" war 2 Mals geschrieben (Ein Mal in VirtualRealityPawn.h und ein Mal in VirtualRealityPawn.cpp).
Das Include (#include "Engine/Engine.h") war 2 Mals geschrieben in VirtualRealityPawn.cpp.

Source/DisplayClusterExtensions/Private/VirtualRealityPawn.cpp

 #include "VirtualRealityPawn.h"
 
 #include "Camera/CameraComponent.h"
-#include "Cluster/IDisplayClusterClusterManager.h"
 #include "Engine/Engine.h"
 #include "Engine/World.h"
 #include "Game/IDisplayClusterGameManager.h"
@@ -10,7 +9,6 @@
 #include "Kismet/GameplayStatics.h"
 #include "DisplayClusterSettings.h"
 #include "IDisplayCluster.h"
-#include "Engine/Engine.h"
 #include "Components/SphereComponent.h"
 #include "DrawDebugHelpers.h"
 #include "Math/Vector.h"